according to hockey-reference, there were 11 first year players with 30 or more goals in '79-'80. but there are two problems with that. first, hockey-reference only counts the first year the player played any games in the league, so guys who played 5 games and then had their real rookie season aren't counted here. second, a most of that 11 were guys who played in the WHA and, thus, not true NHL rookies.

As others have said, 05/06 was the last season. Before that, it was 93/94 with Mikael Renberg (38), Jason Arnott (33), Bryan Smolinski (31) and Alexei Yashin (30). Removing WHA players, the season with the most was 81/82 with 11 players.